The bottom left corner of the device (same side as the windows button, but opposite the power button) seems to have a problem registering touch along the screen. If I touch it just above the task bar (in desktop mode), it registers two touches, usually alternating, about a half inch from each other. Touches closer to the middle will register closer together. About the middle, it works normally.
Trying to run the calibration made touch performance horrible and I had to clear the calibration data.